Inspired by a visit to Vegas, I just checked out Virtual Earth 3D ... very cool! It's a bit slow on my laptop (not sure if it's the laptop or my dismal "high-speed" Internet available at the hotel -- but the wait was worth it:

The view is 3D -- with the ability to select the angle of view and the rotation by holding down the CTRL key.

It does require an install -- but it's relatively small. Make sure you look for the 3D option:

(I don't know what cities have the 3D data though -- I probably lucked out by selecting Vegas).